A considerable number of food poisoning
incidents occur every year in every major community. Such incidents often go unrecognized;
and many recognized incidents are not reported to the health authorities. But occasionally
the nature of the illness is so distinctive, the latent interval sufficiently short, and
the numbers of people involved and the circumstances are such that a number of victims
report their illnesses to the health department. These are the visible part of the food
poisoning "iceberg", and it is imperative that all such reports be carefully
received and recorded on a standard Food Poisoning Report form, by the epidemiologist, a
designated public health nurse or sanitarian. Each report should then be promptly examined
by the community epidemiologist, and whenever the nature and circumstances of the reported
illness warrants it, an appropriate investigation must be quickly performed, initially by
telephone. Often an investigation is triggered by a cluster of two or more reports closely
associated in nature, time, and place.

Herewith a number of food poisoning investigation reports from my files, which may be
useful for neophyte epidemiologists when confronted with similar incidents:

Occasionally we received bogus reports of food-borne illness; some from
obvious cranks, or persons seeking to develop a basis for suing a restaurant or
manufacturer; which wasted the time of one or more of us. And not infrequently, someone
would bring a can or bottle with dubious contents and demand that we analyze the contents
"for any poisonous substance". To do such an open-ended examination for every
conceivable poison that might be in a specimen would require exorbitant expenditure of
laboratory and manpower resources. But if we summarily refused to examine any such
specimen, the offended party might soon complain about our disinterest to political
officials, with repercussions. Hence, we ordinarily accepted such specimens, to be held in
a refrigerator or freezer pending submission of one or more stool specimens, By requiring
submission of a designated number of stool specimens before undertaking any extensive
laboratory examination requested, we fended off many cranks  few of whom are willing
to go to the trouble of submitting multiple stool specimens.

During my seven years with the Seattle-King County Health Department, I
investigated many food poisoning outbreaks, some of which were quite memorable; and for
some of which I have found reports. One such I remember, but for which I do not yet find a
report, was from "The Maison Blanche" restaurant (no longer operative). It came
to my notice because a number of prominent business persons who ate lunch there became
sufficiently ill with high fever and diarrheal illness that they were hospitalized, and
Salmonella Typhimurium isolated from their feces. These cases were reported to the health
department. From the known cases and luncheon companions, I obtained sufficient food
consumption histories that the crab salad was clearly identified as the offending vehicle.
I then visited the restaurant, examined the facilities, obtained additional histories, and
obtained rectal swabs from each of the nine food preparation personnel in the kitchen. All
of these specimens subsequently yielded the Salmonella organism  thus suggesting
that the kitchen help also became infected from the common vehicle. When meeting with the
manager of the restaurant, I queried him concerning the source and handling of the crab
meat used in making the salads. He then showed me cans of the Alaskan crab ordinarily
used; and added that he, personally, had ceased eating crab since he visited an Alaskan
crab cannery two years earlier. There, the daily catch was first steamed, then shelled by
native women; with the meat then placed in # 10 cans, frozen and transported to markets in
Seattle and elsewhere. While visiting the cannery he observed one of the crab workers,
whose child was playing nearby, help the child defecate; after which she picked-up the
stool and tossed it into the bay, and then simply wiped-off her hands before returning to
schucking crab! Because the cooking of the crab meat occurred before the schucking,
any bacterial contamination from schucking was preserved by freezing until eaten. That
realization, plus the taking of rectal swabs from all the cooks, caused me to lose my
appetite for crab salads during some years! The Maison Blanche outbreak demonstrated how
restaurants  through no fault of their own -- may produce food poisoning outbreaks
due to faulty handling of food stuffs at any prior point in the long food chain.